Cambridge O Level Mathematics (Syllabus D) · Syllabus 4024 · Trigonometry
Pythagoras’ Theorem
What is Pythagoras’ Theorem?
The relationship between the three sides of a right-angled triangle: the square on the hypotenuse, the side opposite the right angle, equals the sum of the squares on the two shorter sides. Written a squared plus b squared equals c squared, with c the hypotenuse, it converts any two known sides into the third, and it applies only where a right angle is given or has been established.
This definition is part of the Trigonometry chapter in Cambridge O Level Mathematics (Syllabus D).
Questions students ask about Pythagoras’ Theorem
What is the hypotenuse of a right-angled triangle?
The hypotenuse is the side opposite the right angle. It is defined by position, not by length: examination diagrams are generally not to scale, so the longest line drawn on the page may be any side at all. Find the right-angle marker first, then look straight across from it. In Pythagoras’ theorem, \(a^2+b^2=c^2\), \(c\) is always this side, and a calculated hypotenuse must come out longer than either shorter side.